The present disclosure relates to methods of dispensing underfill material for stacked semiconductor chips, and structures for effecting the same.
In three-dimensional stacked structures including a plurality of semiconductor chips attached to a substrate, it is preferred that the gap among the plurality of semiconductor chips be as small as possible in order to minimize unused area of the substrate. The substrate can be a interposer substrate or a packaging substrate. Reduction of the gap between neighboring semiconductor chips increases the percentage of the area of the substrate that is used for stacking semiconductor chips, and thus, reduces manufacturing cost.
As the width of the gap decreases, however, it becomes difficult to fill the gap with the underfill material through underfill dispensing methods known in the art. Particularly, when the gap becomes smaller than the diameter of a needle of an underfill dispenser, the needle cannot be inserted into the gap for effective dispensing of the underfill material.